This is a double-blind, placebo-controlled, parallel-group, 3 month trial followed by a 3-month open-label period, of a nutritional supplement designed to improve brain metabolism and function in patients with Alzheimer's disease (AD). The design of the nutritional supplement is based on replicated observations of abnormalities in mitochondria in AD. The constituents of the nutritional supplement are components of the normal American diet, and are classified by the FDA as GRAS (Generally Regarded As Safe). Results with the supplement have been favorable in preliminary, open trials (eg mean improvement in MMSE score of +4.9, range +3 to +8, n = 7, P <0.0004).